A terminal fitting is connected to an electric wire conductor at an end of a covered electric wire to be arranged in a vehicle such as an automobile. In an electrical connection portion where the electric wire conductor of the covered electric wire and the terminal fitting are electrically connected, there is a need to prevent corrosion. In particular, when different types of metal materials are in contact with each other in the electrical connection portion, there is a possibility that dissimilar metal corrosion will occur. In some cases, aluminum or an aluminum alloy is used as a material of the electric wire conductor of the electric wire to be used in a vehicle in order to reduce the weight of the vehicle. On the other hand, copper or a copper alloy is often used as a material of the terminal fittings. In addition, the surface of the terminal fittings is often plated with tin or the like. In this case, dissimilar metal corrosion is likely to become an issue in the electrical connection portion where an aluminum-based metal is in contact with a copper-based metal or a tin plating layer. Therefore, corrosion in the electrical connection portion needs to be reliably prevented.
The electrical connection portion may be covered with an adhesive resin in order to prevent corrosion in the electrical connection portion. For example, Patent Document 1 discloses that a resin cover portion is formed so as to cover the entire circumference of a crimped portion where an aluminum electric wire and a connection terminal made of a copper-based material are crimped together. The resin cover portion includes a polyamide resin as a main component, and is specified to have predetermined physical properties.